IRF Uppsala
Space Plasma Physics
Rosetta (English)
...LAP team
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Rosetta (svenska)
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INSTITUTET FÖR RYMDFYSIK Space Plasma Physics programme, UPPSALA
Swedish Institute of Space Physics (59o50.272'N, 17o38.786'E)

LAP logo Rosetta is an ambitious project catching up with a comet, following it in its orbit for two years (2014-2016), putting a lander (Nov 2014) and finally itself onto the surface of the comet nucleus. Our onboard space weather station LAP was active from start to end!
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Rosetta LAP

Science with LAP

The basic goal of Rosetta is to study the origin of comets, the relationship between cometary and interstellar material and its implications with regard to the origin of the Solar System. The main task of LAP is to investigate, together with all the other sensors of the Rosetta Plasma Consortium (RPC), the plasma environment of the comet, to solve riddles related to the comet nucleus itself as well as to its interaction with the solar wind. The basic parameters measured by LAP are the density, temperature and flow speed of the plasma, but other parameters can also be estimated (read more on LAP capabilities below). We fly a similar instrument, though with one probe only, on the Cassini spacecraft now orbiting Saturn.

LAP capabilities

A plasma is a gas of consisting of charged particles. The basic idea of a Langmuir probe is to determine the density of a plasma in the following way:
  1. Put a conducting probe in contact with the plasma (we use nitrified titanium spheres).
  2. Apply a voltage on the probe (a bias voltage). 
  3. Measure the current flowing to the probe from the plasma. The denser the plasma, the higher the current. Voila!
Not only density can be measured, but also temperature, drift speed, effective particle mass, electric field, dust flux...

Science studies

There is still a long way to go to the comet, but we already have some results published:
last modified on Tuesday, 29-Mar-2011 14:11:21 CEST